1. Field of the Invention
This invention relates to a round-shaft cutter with a cutter head and a cutter shaft, wherein the cutter head has a cutter tip which is inserted with a base element into a receiver of the cutter head and is there fixed in place.
2. Description of Related Art
A conventional round-shaft cutter is known from German Letters Patent 37 01 905.8-09. The base cutter body made of steel has a receiver for the hard alloy cutter tip in the area of the cutter head. The cutter tip is soldered into the receiver. Such a round-shaft cutter is used, for example, for cutting road surfaces. Individual cutter tips can break out of their receivers, in particular when working very hard road surfaces. Thus, the cutter head of the base cutter body, which has a much softer material than the cutter tip, is rapidly ground down. The round-shaft cutter, however, is seated in a cutter holder. If the cutter head is now ground down, the cutter holder is damaged. This requires cost-intensive repairs.
It is one object of this invention to provide a round-shaft cutter of the type previously mentioned, which is distinguished by good wear resistance.
This object is achieved with a recess cut into the cutter head in an area of the receiver below the base element of the cutter tip. A wear-protection element is there inserted into the recess and fixed in place.
If the cutter tip of the round-shaft cutter breaks off because of high stress, the additional wear-protection element assures an emergency operating capability until the following tool change. Accordingly, the wear-protection element prevents the rapid wear of the cutter head, so that the cutter holder is protected.
The round-shaft cutter in accordance with this invention also has advantages where the tool change takes place, past the longest permissible length of use. In this case, with the cutter tip worn down, the wear-protection element protects the cutter holder over a defined transition time.
According to one preferred embodiment of this invention, the receiver for the cutter tip and the recess are designed dynamically balanced with respect to the axis of rotation of the round-shaft cutter. The rotatory properties of the round-shaft cutter are not affected because of the symmetrical design of the cutter.
In one embodiment of this invention the cutter can for example be constructed so that the receiver is cut in a plate shape into the cutter head and has a support surface for the cutter tip which extends vertically with respect to the axis of rotation of the round-shaft cutter. The recess is cut into the support surface and the wear-protection element ends flush with the support surface.
However, it is also conceivable that the wear-protection element rises with a projection above the cutter head in the direction of the axis of rotation of the round-shaft cutter. The cutter tip has a depression into which the projection extends. In this case the projection of the wear-protection element also absorbs transverse forces acting on the cutter tip, crosswise with respect to the axis of rotation of the cutter tip. This aids the fastening of the cutter tip on the cutter head.
For simplifying the assembly, on an end of the wear protection element facing away from the cutter tip the wear-protection element has a bevel-like taper.
A round-shaft cutter in accordance with this invention can be designed so that the wear-protection element is made of a hard alloy and is soldered into the recess.